Installer Manual
SMT 770 Chameleon Multifunction Thermostat
Ver 1.21
This document it not typically left with the user as it contains information on setting values which, if not correctly set may damage the heating, cooling or air conditioning system or seriously affect its performance or energy consumption.
Great effort has been taken to making the SMT 770 thermostat system intuitive, reliable and easy to install. Using a common sense approach to the installation will ensure this product is installed easily and to the customer’s satisfaction. Please read and understand this instruction manual so that installation, testing and commissioning process is undertaken in an efficient and effective manner.
This manual is to be used in conjunction with the supplied user manual.
Great care has been taken in the preparation of this manual. Smart Temp Australia P/L takes no responsibility for errors or omissions contained in this document. It is the responsibility of the user to ensure this thermostat, or the equipment connected to it is operating to their respective specifications and in a safe manner.
Due to ongoing product improvement Smart Temp Australia P/L reserves the right to change the specifications of the SMT 770 thermostat (or its components) without notice.
All rights reserved. © Smart Temp Australia P/L 2006 Intellectual rights apply.
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Table of Contents
Installation .................................................................................................................. |
4 |
Mounting the wall controller.............................................................................................. |
5 |
Setting the hardware switches ........................................................................................... |
6 |
TT Terminal Functions .................................................................................................. |
9 |
Outside Air Sensor wiring ................................................................................................. |
10 |
Remote Air Temperature sensor wiring............................................................................10 |
|
Averaging Temperature sensors ....................................................................................... |
11 |
Remote ON / OFF function ............................................................................................... |
11 |
Using the “Occupancy Mode ............................................................................................ |
11 |
Supply Air Temperature Monitoring ................................................................................. |
12 |
Typical Drawings........................................................................................................ |
12 |
Attaching the thermostat........................................................................................... |
17 |
Advanced Installer Settings ........................................................................................ |
18 |
Commissioning .......................................................................................................... |
30 |
Using Remote Temperature Sensors........................................................................... |
33 |
Advanced Functions ................................................................................................... |
34 |
Specifications............................................................................................................. |
38 |
Sensor Reference Table .................................................................................................... |
38 |
Troubleshooting......................................................................................................... |
39 |
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Installation
As with any air conditioning project undertaken, careful installation is the key to a successful outcome. Time taken during this installation process will be rewarded with a happy customer and fewer call backs.
The steps required to install the SMT 770 thermostat are
1.Read and understand this manual and the User manual.
2.Mount the SMT 770 back plate in a suitable location.
3.Set the 8 DIP switches to match the need of the project / user.
4.Wire the optional remote temperature sensor(s) or switches if required.
5.Power up the air conditioning system.
6.Set the installer software options (if required).
7.Program and set up the SMT 770 thermostat. (The User Manual will assist with this).
8.Test the heating, cooling and other functions – Commissioning.
For convenience the layout of this manual is in the same order as the steps listed above.
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Mounting the wall controller
The SMT 770 can only be as accurate as the onboard temperature sensor, or its optional remote temperature sensor(s) permit. It is therefore essential that the wall thermostat be installed in a location that is typical of the ambient room temperature. Do not install the thermostat in a draft, near a floor, behind doors or on a non insulated external wall. Also avoid placing the thermostat in areas where the air movement is limited, affected by direct sunlight or other areas not “typical” of the temperature of the room.
Further, when mounting the SMT 770 be aware that drafts may travel down the inside of cavity walls, (especially if mounted on external walls) and enter the back of
the thermostat or sensor enclosure through the cable entry holes in the wall. It is important to fully seal these holes to prevent any drafts affecting the
internally mounted temperature sensor. It is recommended to mount the SMT 770 or remote sensors between 1.5 & 1.7 metres from the floor where possible.
Move the control wires through the large opening in the thermostat base plate then place the thermostat base on the wall and using appropriate screws, firmly attach the thermostat base to the wall. Seal any holes where cables enter the back of the thermostat to prevent drafts entering through these holes affecting the sensor.
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Setting the hardware switches
Switch |
Off |
On |
Sw1 – Fan Speeds |
1 Speed Fan (2 heat / 2 Cool) |
3 Speed Fan (1 heat / 1 Cool) |
Sw2 – Equipment Type |
Heat Cool |
Heat Pump (O/B terminals) |
Sw3 – Stages |
1 Stage |
2 Stages |
Sw4 – Reversing Valve |
Energise in cool (O) |
Energise in heat (B) |
If Sw 2= ON – Heat Pump |
|
|
Sw4 – Fan Mode |
Fan Control by Heater (HG) |
Fan Control by T’stat (HE) |
If Sw 2= OFF – Heat/cool |
|
|
Sw5 – Anti cycle timer |
Off |
4 Minutes |
Sw6 – Operation |
Manual Thermostat |
Programmable Thermostat |
Sw7 – Minimum Run |
2 minutes |
6 Minutes |
Sw8 – Program Type |
Commercial Program |
Residential Program |
If Sw 6= ON – Programmable |
|
|
Sw8 – Set points |
Single Set point |
Two Set points |
If Sw 6= OFF – Manual |
|
|
Typical drawings have been provided on page 12 of this manual that will assist with the selection of the correct positions for these function switches.
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Switch 1 – Relay Assignment
The SMT 770 is fitted with 5 relays capable of switching up to 24VAC @ 1Amp. Switch 1 sets the function as either 3 fan speeds with 1 heat and 1 cool operation or single fan speed with 2 heat and 2 cool, in either HP (Heat pump or reverse cycle) or HC (heat with add on cool) mode.
Switch 2 – Equipment Type.
Both heat with add on cool or heat pump types of systems can be controlled by the SMT 770.
Heat Cool System uses the “W” terminal(s) only for heating and the “Y” terminal(s) only for cooling.
Heat Pump systems use the “Y” terminal(s) for BOTH heating and cooling. The “W1” terminal to control the reversing valve which determines heating or cooling mode.
Switch 3 – Equipment Stages.
When it is necessary to control a single stage system A/C system fitted with auxiliary heating elements, turn sw3 OFF thereby selecting single stage mode. Heating elements controlled by the W2 output are now assigned stage 2 heat.
Switch 4 – Reversing valve or Fan mode
When the SMT 770 is set for Heat Pump mode (Sw2 is on) then this switch sets the reversing valve logic (O/B). When the SMT 770 is set for Heat Cool Mode (Sw2 is off) then this switch sets the mode for the Heater fan logic (HG or HE mode).
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Switch 5 – Anti Cycle Timer
To protect some A/C systems it is preferred that under no circumstances should the compressor start within 4 minutes of it switching off.
Note, when power is first applied to the SMT 770 it “assumes” that the compressor has just stopped and applies this anti cycle delay time before starting.
Switch 6 – Thermostat Operation
To suit the varying requirements of the user, the SMT 770 can be set as a programmable thermostat using the time clock to automatically control the building temperature to a programmed temperature profile, or to the very simple to operate manual mode where the user turns the thermostat on or off, and adjusts the temperature set point manually.
Switch 7 – Minimum Run time.
To conserve energy and protect the A/C system it is recommended to limit the number of times the heating and or cooling system can run in 1 hour. This switch sets the minimum heating and cooling equipment to a minimum run time of 2 or 6 minutes. Once the heating or cooling has started it must run for this minimum set time. The LCD will flash the word “Heating” or “Cooling” whenever this timer is in effect.
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Switch 8 – Thermostat Control Logic.
This switch also has two functions based on the position of switch 6. When the SMT 770 is set as a programmable thermostat switch 8 determines whether a commercial program or residential program is selected. When switch 6 has the SMT 770 used as a non programmable thermostat, this switch sets single set point mode (imitating a simple mechanical thermostat) or whether a separate heating and cooling set point can be selected by the user. Two set point mode also permits the user to select a separate day and night set point if required.
TT Terminal Functions
The SMT 770 is fitted with a set of terminals marked “TT”. Detail on the functions that the “TT” terminals perform is provided below. See the advanced installer setting menu on page 18 of this manual for setting the function of this set of terminals. The wiring used in the following examples are not polarity dependent and do not normally require screened cable.
Note: The SMT 770 can use multiple sensors if required. Drawings showing these various configurations are shown on page 33 of this manual.
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Outside Air Sensor wiring
Set “TT= OA” in the advanced installer menu.
The SMT 770 can display the outside air temperature if desired. Some advanced control functions such as high and low balance points rely on this sensor to be fitted for correct operation. Using a single pair of wires
connect the “TT” terminals in the SMT 770 to the two terminals in the outside air temperature sensor. (See figure 1). If the outside air sensor fails two dashes will be shown on the LCD where the outside air temperature would normally be displayed to alert you of the problem.
Remote Air Temperature sensor wiring.
RS-01
Set “TT= RS” in the advanced installer menu. When you wish to measure the temperature from a location distant from the wall controller, simply
connect a remote temperature sensor to the “TT”
terminals in the SMT 770. This will automatically disable the sensor fitted to the wall controller and use the remote temperature sensor(s) to control the room temperature (See figure 1 above). Should you wish, you can easily switch the remote temperature sensor on and off thereby switching temperature sensing locations between the remote temperature sensor and the SMT 770 temperature sensor when required. Simply fit an inline switch in the sensor wiring or order Smart Temp part number RS 01S sensor. (See Figure 2.)
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Averaging Temperature sensors
Set “TT= AV” in the advanced installer menu.
The SMT 770 can average the sensed temperature equally between the remote temperature sensor(s) and the one fitted to the SMT 770 if required. See figure 1 on the previous page for details on wiring the sensor. The SMT 770 will auto detect this sensor and automatically average the two sensors values to control the room temperature.
SMT-770 On/OFF Switch
Remote ON / OFF function |
T |
|
T |
Set “TT= OF” in the advanced installer menu.
Figure 3
The SMT 770 can be connected to an external dry contact, when this
contact is closed the SMT 770 will turn OFF. See figure 3. When the SMT 770 has been switched OFF via the “TT” terminals the word “OFF” will flash in the LCD to indicate that this has been the shutdown method. The SMT 770 will return to the user settings when this switch is open.
Using the “Occupancy Mode
Set “TT= OC” in the advanced installer menu.
The SMT 770 can alternate between the user preferred set points and an installer pre programmed set point when required. Simply wire a remote switch to the SMT 770 “TT” terminals, (see figure 3). When the switch is open the user settings will control the room temperature, when the switch is closed the Installer “Oc” (Occupied Cooling value) & “Oh” (Occupied Heating value) settings will be used to control the room temperature.
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Supply Air Temperature Monitoring
Set “TT= DA” in the advanced installer menu.
In this mode, the SMT 770 will broadcast this sensor temperature value to Modbus ONLY, this value is not used by the SMT 770 nor is it displayed on the LCD. It is expected that this information is used for supervisory functions or equipment control feedback. Also, as this is an analogue input, by monitoring a switched resistor network your supervisory software can decode a number of digital states.
Typical Drawings
The SMT 770 has the capacity to control a wide selection of heating, cooling and air conditioning systems. Using the 8 DIP switches and many installer software options, the SMT 770 is capable of providing more than 135 different control methods from its 5 fitted relays. Examples of only the most common types of control wiring have been provided below.
You may need to modify these drawings slightly to specifically suit your individual needs, alternatively contact Smart Temp at support@smarttemp.com.au or an authorised distributor for installation information specific to your application.
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Switch Settings
Sw1 = Off (1 speed fan) Sw2 =Off (HC System) Sw3=Off (Single Stage) Sw4= Off (HG)
Sw5= Installer preference Sw6= User requirements Sw7= Installer preference Sw8= User requirements
Tip
Set Installer menu Fn=H
Figure 4
Switch Settings
Sw1 = Off (1 speed fan)
Sw2 =Off (HC System)
Sw3=Off (Single Stage)
Sw4= N/A
Sw5= Installer preference
Sw6= User requirements
Sw7= Installer preference
Sw8= User requirements
Tip
Set Installer menu Fn=C
Figure 5
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